Cook the potatoes in their skins until just tender. Remove the hot peel and cool in a plastic bag.
Steam shallots in a little butter until translucent. Add parsley and capers, mix, cool.
Just before serving, finely grate potatoes. Mix with salt, salmon, shallot mixture and pepper. Form equal-sized portions. Toast in remaining butter, turning, until crispy brown.
Serve: Serve with salmon. Serve with apple puree and/or sour cream.